lures 18 times in the first 3-minute interval, 9 times in the second, 

 11 times in the third, and 3 times in the fourth. 



These and other kymograph records are analyzed more 

 extensively in the sections which follow. 



School Entrances 



The activity under various conditions of stiinulation may 

 be measured by the number of schools (of varying size) entering the 

 attraction area during a 15-minute period. The results of the ex- 

 periments are summarized in table 4. In this, and other tables to 

 follow, the data for September 5 and 9 have been adjusted to a 15- 

 minute periodc The results for similar experiments conducted on 

 the same day have been averaged. 



It will be seen that on each day schools entered the 

 attraction area more frequently (as compared with control conditions) 

 when a pair of colored lures was dipped into the water, and still more 

 frequently when lures were used together with extract. The grand 

 mean number of entrances was 6=7 for controls, 14„ 6 for lures, amd 

 21.6 for lures plus extract. Obviously the differences between the 

 means are statistically significant. 



Table 4, ==Summary of data on the number of 

 schools entering the attraction area 

 under various conditions of stimulation 



Condition 



Control 



Lures 



Lures plus 

 extract 



9/3 



38,25 



9/5 



10 I 5 

 19,25 13 



2U25 



Date 



9/8 

 9 



22,33 



9/10 



3 



12,5 

 14,00 



9/12 



7 

 16 

 16,75 



9/17 



6 

 12 

 17 



Mean 



6,7 

 14. 6 

 21.6 



Percentag e of Time in Area 



The percentage or relative time spent by the fish in the 

 attraction area is summarized in table 5 for the various conditions 

 of stimulation. On the average the time spent in the area was 12, 



70 



